Caster



FIG. 1 is a perspective view of a caster showing the new design;

FIG. 2 is a side view of the caster shown in FIG. 1;

FIG. 3 is a front view of the caster shown in FIG. 1;

FIG. 4 is a rear view of the caster shown in FIG. 1;

FIG. 5 is a top view of the caster shown in FIG. 1; and,

FIG. 6 is a bottom view of the caster shown in FIG. 1.

The ornamental design for a caster, as shown and described.